Heat exchanger



Nov. 11, 1958 R. L. CALLARD 2,859,948

HEAT EXCHANGER Filed Aug. 26. 1954 m cgi/m /Q (ttorneg United :SoresPaf-af HEAT EXCHANGER Robert L. Callard, Painted Post, N. Y., assignortn Corning Glass Works, Corning, N. Y., a corporation of New YorkApplication August 26, 1954, Serial No. 452,415

2 Claims. (Cl. 257-236) The present invention relates in general tofluid seals and more particularly to heat exchangers, of the shell andtube type provided with fluid seals embodying the invention.

According to the invention, as applied to a shell and tube type of heatexchanger unit, the tubular shell near each end opening is provided witha lateral branch surrounding a side opening. The wall surrounding theopening in each instance has exterior surfaces which Bare in aconventional fashion to facilitate, with the aid of suitable ttings, theready clamping of the unit to another in either a vertical or horizontalstack. Fluid seals bridge the spaces surrounding the usual tubesextending through the shell and in communication with the shellinterior, from communication with shell end members in communicationwith such tubes. Each uid seal includes a pair of spaced apertureplates, of glass or other highly corrosion resistant ceramic material,clamped between an end of the shell and an adjoining shell end memberand through which the tubes occupying the shell freely pass. Such tubesin the region between such plates are surrounded by tubular wall portions of high durometer polytetrauoroethelene sealing members which arenon-sticky and therefore readily slidable with respect to the engagedtube wall, shell and plate surfaces during contraction and expansion ofthe shell and tubes as occurs in ordinary use. Moreover, they are inertto most corrosive fluids and capable of safely withstanding temperaturesup to 500 F. Such members are held in sealing engagement with the wallareas of the tubes surrounded and with the plates through which theypass by hydraulic pressure applied to their opposite surfaces. Suchpressure is applied, by displacement of a plastic body or a body of lowdurometer material such as silicone base synthetic rubber confinedwithin the remainder of the space between such plates, and compressedtherebetween as they are clamped between a shell end and a shell endmember. The above rubber, while less inert to corrosive materials thanpolytetrafluoroethelene, is likewise unaffected by prolonged exposure totemperatures up to 500 F.

A further feature of the invention is the employment of tubes that arethick-walled in their end regions, so as to enable them to withstandlthe compression thereabout resulting from the clamping of the parts toone another, but which are thin-walled within the shell body for highestpossible heat transfer efciency. l

For a better understanding of the invention reference is made to theaccompanying drawing in which:

Fig. 1 is a side elevation of a heat exchanger embody- Patented- NOV-11's ing the invention and in which two shell units are shownstackedhorizontally, and part of one unit being shown in section.

In detail, each unit of an assembly comprises a glass' shell 11 havingend openings bordered with a wall whose exterior surface 12, is,outwardly flared toward the end:

to form a seat for a clamping member such as 13 pro` vided with asuitable glass engaging cushion 14. A plurality of glass tubes such as21 occupy shell 11 and have reduced diameter thick-wall portions such as22 projecting through the open ends thereof. Desirably such tubes are inpart supported at intervals along their length by suitably perforatedbailles 20. As will be noted from Fig. l such baflles are arranged inthe shell in a manner to provide an undulating cross flow of uid passingthrough the shell about the tubes.

The end portions such as 22 of the tubes 21 pass through alignedapertures in spaced plates 23 and 24 arranged betweenpolytetrauoroethelene gaskets 26 and 25 adjacent the ends of shell 11and a shell end member such as 27. Arranged between plates 23 and 24 arefluid sealing members each having disc portions such as 32 surroundingtubular portions such as 33 closely fitted about the tube portions suchas 22 and with their disc portions arranged against the opposingsurfaces of the respective plates so as to bridge the passage spacesremaining between the tubes and such plates. The remaining space betweenplates 23 and 24 is lled with a low durometer rubbery body 35 confinedtherein by a metal band or clamp such as 37 bridging the outer connes ofthe space between such plates and slidably tted there about.Accordingly, when an end of a pipe or shell 11 and a shell end membersuch as 27 are clamped against the described assembly including plates23 and 24, as is done through the medium of clamping member 13, asimilar member 36 and a number of bolts such as 46 and springs such as47, the body 35 of low durometer liquid is displaced under thecompression of such springs against the high durometer member portionssuch as 32 and 33, which are in turn snugly pressed against thesurrounded tube ends 22 and against the adjacent plates. Su'ch highdurometer members accordingly maintain the spaces surrounding therespective tubes sealed while a1- lowing freedom of relative movement ofthe respective parts during temperature changes of the structure thatoccur in the usual course of its use.

As will be understood, although the seals as illustrated and describedbridge spaces surrounding tubes passing through plates, the provision ofseals between adjoining elements of any desired shape is within theconcept of the invention. As will be appreciated it is only necessarythat a sealing strip of high durometer material bridge the line ofjuncture of such elements, to back up such material with a confinedliquid body of a low durometer material and to provide facilities forsuitably compressing the liquid body against the sealing strip.

What is claimed is:

l. An assembly which includes a tubular shell having a tubular bodypassing therethrough, a fluid tight closure for the shell endsurrounding the tubular body, said closure including a pair of similarspaced rigid plates extending transversely of an end of the shell andhaving aligned passages through which an end region of sad tubular bodyfreely passesrub,b,ery sealingdiscsoi high.

durometer material each having a tubular portion occupying the spacebetween said rigid plates and whose passage is closely confined aboutsaid tubular body and occupies the space between said plates and whosedisc portions bridge the spaces around the rigid plate passages throughwhich the tubular body is passed, an endless band bridging the outer:connes of the space between such plates, a body of` relatively lowduprorneter material occupying thev remainder off the space betweensaid? plates, andi a single` means for urging said plates toward oneanother and toward the adjacent shell* endwherebythe body of:lowdurometer'material? displaces the relatively high durometerfmaterial' members i'nto intimate iiuidv sealingengagement with the'surrounded surfaces` of said: rigidi plates; respectively.

2. An assembly such as defined by claim 1 wherein the wallY thicknesslof the tubular body isY greatest` inthe end regions thereof.

References Cited in the file of this patent UNITED STATES PATENTS1,412,056 Hughes et al. Apr. 11, 1922 1,575,497 Meschke Mar. 2, 19262,196,683 Pickstone Apr. 9, 1940 2,313,308 Allen Mar. 9, 1943 2,467,312Jack Apr. 12, 1949 2,504,496 Carter Apr. 18, 1950 FQREIGN' PATENTS406,584 Great Britain Mar. 1, 1934 821,798 Germany Nov. 19`, l9-51'

